New melanoma mutations may give clues to how cancers spread

Researchers have pinpointed mutations in melanoma tumors in a part of the cancer genome where mutations previously have never been found, marking a milestone in how the basic science of this deadly type of cancer is understood.

Scientists at Boston's Dana-Farber Cancer Institute have found two new mutations that jointly occur in 71% of malignant melanoma tumors in what's known as the "dark matter" of the cancer genome. The findings, published in the Jan. 24 issue of Science Express, are significant because the recurring mutations may be the most common mutations in melanoma cells ever found.

By searching the entire DNA of multiple tumors, scientists identified the new cancer-associated mutations in the 99% of "junk" DNA in cancer cells that do not contain genetic instructions for making proteins. Instead, the mutations are located in nonprotein-coding DNA that regulates the gene activity.

The mutations affect a stretch of DNA code that regulates the expression of a gene next to the TERT gene. TERT contains the recipe for making telomerase reverse transcriptase, an enzyme that can make cells virtually immortal, and is often found overexpressed in cancer cells.

"Altogether, this discovery could cause us to think more creatively about the possible benefits of targeting TERT in cancer treatment or prevention," Levi Garraway, a Dana-Farber researcher and the article's senior author, said in a statement.

While the discovery does not immediately imply new treatments for the disease--named by the National Institutes of Health as the most dangerous type of skin cancer and the leading cause of death from skin disease--it does help explain how the cancer grows and develops. In the long-term, this could be a key piece of the puzzle in finding ways to prevent or stop the cancer.

- get more in the New York Times story
- here's the press release